Boletales » Boletaceae » Borofutus

Borofutus dhakanus

Borofutus dhakanus Hosen & Zhu L. Yang, in Hosen et al., Fungal Diversity 58: 219 (2012)

Etymology: dhakanus refers to the name of type locality (Dhaka).

 

Basidiomata small to medium-sized. Pileus 3065 mm, convex when young, becoming plane with age, covered with light brown (6D8) to cocoa brown (6F7), grayish brown (6F34) to dark grayish brown (6F67) squamules, which become grayish black (6F1) at maturity; center sometimes umbilicate, depressed, not glabrous, becoming rimose with age, dry, somewhat slightly tacky when wet, margin occasionally uplifted. Hymenophore tubular, subdecurrent, pallid to creamy to yellowish (4A12), turning pale reddish to pale reddish purple on exposure to air for long time when young, becoming light brown (6D68) to golden brown (5D78) at maturity; pores 511 mm depth, 410 mm length and 26 mm wide, sometimes double-pored, mostly hexagonal, relatively broader towards the centre then gradually narrower towards the margin, with reddish powdery mass inside the tubes when aged. Stipe 2540×612 mm, central, cylindrical, narrowly tapering upwards, occasionally slightly swollen to the base, mostly curved, covered with purplish to grayish to cocoa brown squamules; apex glabrous, whitish to creamy to yellowish; upper half ribbed by the subdecurrent lines of the hymenophore; basal mycelium whitish. Context 515 mm thick in the center of the pileus, solid, yellowish to creamy, usually unchanging when bruised but in some specimens turn pale reddish to pale reddish purple when exposed to air for long time. Taste unknown and Odor mild.

Basidiospores [320/16/16] (10) 1113 (14) × (4.5) 56 (6.5) μm, [Q= (1.97)2.082.52(2.92), Qm= 2.29 ± 0.16], boletoid to somewhat amygdaliform, slightly thick-walled (0.7 μm), brown-violet to purple to purplish red (11C68, 11D68) in H2O, purplish violet (11E58, 11F58) in 5 % KOH; surface finely verrucose under light microscope (LM), but ornamented with irregular to regular, conspicuous shallow pits under SEM. Basidia (20) 3133(39) × (7) 910(12) μm, narrowly clavate to clavate, hyaline to pale yellowish in H2O and glycerin, thinwalled, tetrasporic, occasionally 2- or 3-spored, bearing relatively long sterigmata (5.08.5 μm long). Hymenophoral trama 110170 μm wide, bilateral; hyphae cylindrical, hyaline, 720 μm wide. Cheilocystidia abundant, (45)7080(100) × 714 μm, narrowly lageniform to lageniform to broadly lageniform, sometimes narrowly utriform to mucronate, rostrate, slightly thick-walled (0.61.2 μm thick), with an attenuate appendage, sometimes with a secondary septum; inner surface often with brown to greenish brown pigmented ornamentations. Pleurocystidia 85105×1220 μm, thin-walled to slightly thick-walled (up to 0.5 μm thick), scattered, narrowly lageniform to broadly lageniform with an appendage-like apex, without encrustation. Pileipellis a trichoderm when young, becoming a subcutis at maturity, composed of 45 long cylindrical cells; terminal cells 2560(−105)×510(−13) μm, with brown to chocolate brown vacuolar pigments. Stipe trama composed of vertically arranged hyphae. Stipitipellis a sterile hymenium-like structure, composed of subclavate to clavate to fusiform cells with projecting cystidia (4050×815 μm) with yellowish brown to pale brown vacuolar pigmentation. Clamp connections absent in all tissues.

Habit and habitat: Mostly solitary or often in small groups, and usually found growing in clayey soil rich in Fe in pure stands of Shorea robusta.

Known distribution: Currently known only from Bhawal National Park, Gazipur, Dhaka division, Bangladesh at 20 m elevation.

Index Fungorum number: IF800167

 

Figure 1. Phylogenetic tree generated from nrLSU dataset of 55 sequences in the Boletales using ML method. Posterior probabilities from Bayesian inference (BI) (>0.94) are indicated as thick branches and bootstrap values derived from ML and MP analyses (BS> 50 %) are shown above or beneath the branches at nodes. Parsimony analysis resulted in two most parsimonious trees of 1,726 steps, with Consistency Index (CI) =0.314, Retention Index (RI) =0.506 and Rescaled Consistency Index (RC)= 0.182. GenBank accession number for each sequence is provided behind the species name

 

Figure 2. Phylogenetic tree generated from the combined 5.8S, nrLSU, tef1-α, rpb1 and rpb2 dataset using ML method. Posterior probabilities from BI (>0.98) are indicated as thick branches, and bootstrap values derived from ML and MP analyses (BS>50 %) are shown above or beneath the branches at nodes. Parsimony analysis resulted in two most parsimonious trees of 7,140 steps, with Consistency Index (CI) =0.445, Retention Index (RI) =0.488 and Rescaled Consistency Index (RC) =0.239. Borofutus dhakanus is highlighted in boldface. Herbarium voucher or isolate number is provided behind the species name

 

Figure 3. Microscopic features of Borofutus dhakanus a Basidiospores. b Cheilocystidia. c Pleurocystidia. d Basidia with basidioles. e Surface of stipe in longitudinal section showing caulocystidia. fg Pileipellis. f Trichoderm pileipellis from young basidiome. g Subcutislike pileipellis from mature basidiome. (a, c, d, f and g from holotype, HKAS 73785; b from HKAS 73793; e from HKAS73784)

 

Figure 4. SEM of basidiospores is from dried specimens of Borofutus dhakanus, Spongiforma thailandica and Austroboletus tristis ad Borofutus dhakanus spores with scattered shallow pits. Note: a SEM of basidiospores dipped in 5 % KOH for 2 min remaining its natural behavior. ef Spongiforma thailandica basidiospores with verrucose surface, subtruncated apex with pore. gh Austroboletus tristis basidiospores with complex roughened surface of basidiospores. (a from holotype, HKAS 73785; cd from HKAS 73777; ef from isotype, DED 7873; g-h from holotype, FH, Sheet 3712)

 

Figure 5. Borofutus dhakanus in its natural habitat ab Immature and mature basidiomata with their broad-pored hymenophoral surface. c Small group of basidiomata with their pileus surface. d Unchanged context (image taken immediately after sectioning). e Hymenophoral surface slightly turning pale reddish in some areas over the course of 60120 min. (ab from holotype, HKAS 73785; ce from SHAF 2)

 

Key reference:

Hosen, Iqbal & Feng, Bang & wu, Gang & Zhu, Xue-Tai & Li, Yan. 2013Borofutus, a new genus of Boletaceae from tropical Asia: phylogeny, morphology and taxonomy. Fungal diversity. 58. 215-226. 10.1007/s13225-012-0211-8.

 

About Basidiomycota

The webpage Basidiomycota provides an up-to-date classification and account of all genera of the phylum Basidiomycota.

 

Supported by 

Thailand Science Research and Innovation (TSRI)

project entitled:

"Macrofungi diversity research from the Lancang-Mekong Watershed and surrounding areas"

(Grant No. DBG6280009)

Contact

  • Email: basidio.org@yahoo.com
  • Addresses:
    Mushroom Research Foundation, 292 Moo 18, Bandu District,
    Muang Chiangrai 57100, Thailand
  • The State Key Lab of Mycology, Institute of Microbiology, Chinese Academy of Sciences, No.3 1st Beichen West Rd., Chaoyang District, Beijing 100101, P.R. China


Published by the State Key Lab of Mycology, Institute of Microbiology, Chinese Academy of Sciences and
Mushroom Research Foundation
Copyright © The copyright belongs to the Curators. All Rights Reserved.